Drafting instrument.



110.858.913.l PATENTEDJULY2.1907. RJG. SAUBR.

DRAPTINGINSTRUMENT.

APPLICATION FILED .141", 30, 1907.

I No. 858,913.

UNITED' STATES PATENT oEEIeE;

EoBEE'r c. SAUEE, or LOUISVILLE, KENTUCKY.

Specification of Letters Patent.

Patented July 2, 1907.

Applicant.. un num; 30.1907. stl-a1 nq. 354,819.

To all whom it my'ocmeerm Be it known that I, Bonner G. Sauna, a citizenof the United States of America, residing at Louisville, in the countyof Jefferson and State of Kentucky, have invented new and usefulImprovements in Drafting Instruments, of which the following is aspecification.

This invention relates to a combination drafting instrument wherebystraight or .curved lines, circles, and lines at various angles can beconveniently and readily made or arcs and langles of any degreeaccurately and quickly measured. y

The invention has for one of its objects to provide an instrument ofthis character -in which the moans for accomplishing the variousoperations above mentioned is combined with a T-square ot approvedconstruction.

A- further object of the invention is the provision of a T-square uponwhich is slidably mounted hingedly connected scale blades wherebycircles or arcs of -circles of various radii, lines at any desired angleand arcs and angles may be measuredin degrees with great facilitywithout the use of the usual divider compass,

y beam compass, triangles and protractors.

Another object of the invention is to improve and simplify theconstruction and operation of devices of this character' so as to becomparatively easy and inexpensive to manufacture, readily andconveniently Inanipulated, composed of few parts and designed to enablethe scale blades to be folded under thelblade of aI T-square out of theway when not in use.

With these objects in view as will'appear as the nain elevation. Fig; 3is a vertical transverse section on line 3-3, Fig. 1, dmwn on a slightlyenlarged scale. Fig. 4 is a similar section on line 44,.Fig. 1.

Corresponding parts are indicated by similar reference charactersthrough the several views of the drawings. w

Referring to the consisting of the usual head 2 and the`blade 3, whichis preferably a steelcasting secured to the head l by screws or othersuitable fastenings 4. The blade 3 is provided adjacent therruling edge5 with a slot 6 that extends approximately the full length thereof. Theunder side of the blade is formed with longitudinal ribs 7 which,besides serving to reinforce and stiffen the blade, raise the blade offthe drawing board 'so as to accommodate the scale blades when the latterare folded drawing, 1 designates a 'J3-square into an inoperativeposition, as when they are not rcqui'red and the instrunient is to beused as an ordinary Employed in combination-with the T-square is a pairof scale blades 8 and 9 having their adjacent ends arby the rivet 10.These blades have perfectly straight and smooth -longitudin'al edges andany desired system or systems of divisions or scales may be appliedthereto. Each blade is provided` with an elongated rectangular slot 11extending approximately the full length thcreof. Arranged to slide inone or the other of these slots 11 is a pen or pencil holder designatedgenerally by 12. This holder comprises an axially bored screw or bolt 13having a rounded portion 14 that fits slidably in the slot 11 andengaging the thread 15 is a nut- 16 bearing on one side of the blade 8or 9 with the lieadl'llof the screw bolt bearing on the opposite side.,By loosening the nut 16 the pencil holder can be adjusted to'anydesired position and then secured in place. by tightening the nut.

To change the pencil holder from one scale blade to they other it is, ofcourse, necessary to unscrew thenut entirely and take out the bolt andadjust the holder to the desired blade. The rivet 10 is preferably.provided with an opening 18 for facilitating the obtaining of centersand other points in the various operations of the.

instrument. l p y The scale blade 8 is slidably and pivotally mounted onthe blade ofthe T-square by means oi a slide 19 and a pivot lug on theblade 8 passing through the slide. The slide comprises a semi-circularplate having lugs 20 curled downwardly toenter the slot 6 of theT-square blade as best shown in Fig. 2, the fit being ysuch that aperfectly rigid and accurate movement of the slide 19 is possible.Adjacent the periphery of the slide 19 are arranged degree marksdesignated by 21 after the fashion of an ordinary protractor. The scaleblade 8 which is preferably cast steel has the pivot lug 22 formedintegral therewith and projects upwardly through the slide 19 and throgha Hat quadrant shaped plate 23. The lug 22 is transversely apertured toreceive the pivot pin 24 for the clamping cam 25, said cam beingprovided with a lever 26 for conveniently operating the cam. This camforms a clamping means whereby the scale blade 8 and slide 19 aresecurely fastened in any desired position of adjustment. The quadrant 23has an index mark 27 coinciding with its centerline which coperates withthe scale 21 of the slide 19 for adjusting the scale blades to anydesired angle and for measuring an angle or arc in terms of degrees. Inthe center line of rangedin overlapping relation and hngedly connected ythe quadrant 23 is a depression 28 for receivingthc laterally curved endof the cam lever 26, as best shown in Fig. 2.

From the foregoing description taken in connection with the accompanyingdrawing, the advantages of the construction and of theI method ofoperation will be T-square the blade 9 is first folded over the blade 8and then the cam 25 is unclamped so that the scale blades can be swungunder the T-square blade. The clamping cam is then tightened so as toholdthe blades in place. Horizontal lines can then be drawn by the useofthe 'll-square blade in the usual manner. When it is desired to drawvertical lines or lines between the vertical and horizontal, the scaleblades 8 and 9 are employed. i To draw circles of large radii the pivot22 is used at. its center and a pencil' is placed inthe holder l2 andthe lines drawn by swinging thescales 8 and 9 as 'a single member orunit around the pivot 22. By -adjustng the holder l2 back or forth oneither one of the scale blades concentric circles can be described. lnorder to draw circles of small diameters `the opening 18 inthe rivet 10is used as a center and the blade 9 is swung around to describe thecircle while the pencil is held in the holder 12. By shiiting the holderconcentric circles or arcs can thus be described. To measure an angle orthe length of an arc or circle in degrees the! instrument is. adjustedso that the axis ot the pivot 22 will coincide with the center of thearc or angle and then the scale blade or blades are manipulated afterfirst loosening the clamping cam. For instance, "the scale blade ismoved so as to coincide with one end oi the arc to be measured,and thenthe quadrant plate '23. is adjusted so that the lever 26 will enter thedepression 28 when the cam is tightened. The position of the index line27 on the quadrant is noted with relation to the degree scale 21. Theclamping cam is then loosened and the scale blade adjusted to theopposite end of the arc to be measured. The quadrantplate 23 is againshifted so that the clamping cam can be tightened and the lever 26thereof enter the depression 28 of the quadrant plate.. The position ofthe index line 27 with respect to the scale 21 is noted so that by asimple computation the length of thearc in degrees is obtained.

From the foregoing it will bel seen that the instrument is adapted to alarge variety oi uses, and obviates the need oi several ordinarydraiting implements, such as triangles,scale rule, protractor, Compassesand the like.

I have described the principle of operation of the invention togetherwith the apparatus which I now consider to be the 'best embodimentthereof, and l desire to nation ot a Tsquare,a slotted blade plvotaliyand slidably mounted on the blade of the square, and u. pencil holderslidable on the`siotted blade, said holder comprlsing a longitudinallybored screw bolt, and a nut engaging the bolt.

2. In an instrument of the class described, rthe comblnation of aT-square having a slotted blade, a slide movable on the top surface otthe blade and provided with Vmeans engaging in the slot of the Tsqusreblade, a pair of hlngedly connected scale blades pivotally mounted onthe slide, and a clamping means for adjustably securing the slide andscale blades to the T-square blade.

3. In an instrument of the class described, the comhlnation of s.slotted blade provided with longitudinal ribs on its under surface. andalongitudinai slot, a slide movable on the top surface ot the blade, s.blade pivotoliy mounted on the slide and arranged to fold under theslotted blade, and a clamping means for sdjustablysecuring the slide andsecond lblade ln ilxed position on the slotted blade.

4. in an instrument of the class described, the combination of a'l2-square having a longitudinally slotted binde,

'a slide on the blade having portions engaging the slot of the latter, asecond blade, a pivot thereon extending through the slide from theunderside of the square blade, a plate -on the slide'through which thepivot extends, a clamping cam fuicrulned on the pivot for clamping theslide and second blade to the square blade.

5. in an instrument o! the class described, the combi nation of aT-square having a slotted blade, o. semi-circular slide movable alongthe blade and provided with portions engaging in the slot of the latter,a degree Ascale on the slide adjacent the periphery thereof, a platemovubly mounted on the sllde and provided with an index mark and havinga depression in line with said mark, a slotted secondary blade disposedunder the square blade and provided with a lug extending upwardlythrough the slide sind plate, a clamping device on the ing adapted toengage in the depression of the plate, and a pencil holder adjustublymounted on the secondary blade.

6. In an instrument o! the class described, the combination'of a'il-square having a slotted blade, a slide guided by the slot, a slottedblade pivotnliy mounted on the slide, a third slotted blade arrangedwith one end overlapping the second blade, a hinge connecting theoverlapping portions of said blades and provided with 'an opening, and apencil holder adapted to be used interchangeably on either of thehingedly connected blades.

In testimony whereof, I ailix my signature in presence of two witnesses.

ROBERT c. sauna.

Witnesses:

JOSEPH H. Wnisnunnnosm, GEORGE W. Lucas.

